With a higher and higher requirement of display devices on grayscale, control of the grayscales of the display devices by relying solely on data signals currently has the following problems:
1. When grayscales are higher, the difference of data signals corresponding to adjacent grayscales is smaller, and a high cost needs to be paid for the distinction of such a small voltage using a conventional chip.
2. When the difference of the data signals corresponding to the adjacent grayscales is very small, brightness distinction in display cannot be achieved in the case of insufficient response sensitivity of driving transistors. Therefore, when the grayscale of the display device is higher, the requirement on the sensitivity of the driving transistors is higher, causing the requirements on the manufacturing process, materials and the like to be also very high. The cost is also increased.